Traffic in a mobile communication network has been increasing explosively in recent years as a mobile communication device, notably a smart phone and a tablet terminal, and an application service provided by mobile communication using the mobile communication device have become rapidly widespread. While a mobile communication carrier has started to shift from a 3G (3rd Generation) service to an LTE (Long Term Evolution: registered trademark) service in order to meet the rapidly increasing traffic, it is desired to take further measures against the traffic.
Now, there has been proposed a technique in which, for example, a base station apparatus including a plurality of processing cards corresponding to each area relocates a radio channel of a processing card for which a problem is detected to a processing card covering another area, the plurality of processing cards performing baseband processing on a radio signal transmitted to/from a mobile unit. Moreover, there has been proposed a technique in which, for example, a radio base station including a plurality of processing cards operates an appropriate number of processing cards while adapting to future traffic predicted, the plurality of processing cards performing baseband processing on a transmission/reception signal transmitted to/from a plurality of mobile terminals.    Patent Literature 1: Japanese Laid-open Patent Publication No. 2009-38692    Patent Literature 2: Japanese Laid-open Patent Publication No. 2012-85155
However, the aforementioned technique of the related art lumps together a plurality of functions executing a series of processing on a baseband signal and implements it into one processing card. The processing performed on the baseband signal includes RLC (Radio Link Control) processing defined by a 3GPP (3rd Generation Partnership Project: registered trademark), MAC (Media Access Control) processing, and encoding processing. In order to meet the rapidly increasing traffic, the aforementioned technique of the related art accommodates in one base station apparatus the processing cards, the number of which corresponds to the number of radio resources such as cells or sectors accommodated in a base station or the number of user terminals accommodated in the radio resource.
Accordingly, the aforementioned technique of the related art expands or removes a function according to the traffic per processing card in which the plurality of functions executing the series of processing on the baseband signal is implemented in a lump. The aforementioned technique of the related art therefore has a problem that a hardware resource is assigned excessively depending on the traffic for each radio resource such as the cell or sector when seen by the unit of function, and that use efficiency of the processing card is decreased.